diff --git a/addons/stock/models/stock_move.py b/addons/stock/models/stock_move.py
index b598dde25dd..3abf0979c0a 100644
--- a/addons/stock/models/stock_move.py
+++ b/addons/stock/models/stock_move.py
@@ -877,7 +877,7 @@ class StockMove(models.Model):
             to_update = self.move_line_ids.filtered(lambda m: m.product_id.tracking != 'serial' and
                                                     m.location_id.id == reserved_quant.location_id.id and m.lot_id.id == reserved_quant.lot_id.id and m.package_id.id == reserved_quant.package_id.id and m.owner_id.id == reserved_quant.owner_id.id)
             if to_update:
-                to_update[0].with_context(bypass_reservation_update=True).product_uom_qty += self.product_id.uom_id._compute_quantity(quantity, to_update.product_uom_id, rounding_method='HALF-UP')
+                to_update[0].with_context(bypass_reservation_update=True).product_uom_qty += self.product_id.uom_id._compute_quantity(quantity, to_update[0].product_uom_id, rounding_method='HALF-UP')
             else:
                 if self.product_id.tracking == 'serial':
                     for i in range(0, int(quantity)):